This invention relates to electrocardiography, and more particularly to a positioning device for electrocardiograph sensors that provide a record of the precise location of the sensors on an individual.
In order to take an electrocardiogram recording, electrocardiograph sensors or exploration electrodes are placed on an individual's chest in the vicinity of the heart. The positioning of such electrodes is usually made pursuant to instructions of the instrument manufacturer and the skill and judgment of the person administering the electrocardiogram.
If an individual is to have more than one electrocardiogram taken at periodic intervals, it is desirable that each recording be taken with the exploration electrodes in the same position as the previous recording. A comparison of one electrocardiogram trace with another electrocardiogram trace then becomes more meaningful.
Unfortunately the location of exploration sensors in identical previous positions would require that the individual be tatooed or otherwise marked with the previous position, an impractical and unappealing prospect.
Attempts to deal with the problem of providing a consistent location for electrocardiograph sensors have not yielded an adequate solution.
For example, U.S. Pat. Nos. 4,121,575 and 4,202,344 show an elastic belt-like chest piece used in electrocardiography which has a vertical mark for indicating the mid-chest or mid-sternum and a horizontal mark for indicating the mid-nipple line. However the chest piece, which has six electrode positions, is stretched according to the size of the patient and cannot be otherwise oriented for purposes of exactly locating an electrocardiograph sensor in a repeatable position. Furthermore, these devices do not furnish data for recording the precise electrode positions during the taking of an electrocardiogram.
Other known electrode placement devices such as shown in U.S. Pat. Nos. 4,432,368; 4,457,309; 3,409,007; 3,476,104 and 4,033,303 are intended to facilitate placement of electrodes on an individual but do not deal with the problem of precisely locating such electrodes in repeatable positions on an individual.
In addition to determining repeatable positions for electrode sensors, it is important that the sensors be placed at predetermined locations on the anatomy. Otherwise deviations in an anticipated range of magnitude of electrical potential that have nothing to do with the condition of the heart will occur. A misplacement of the electrode away from a desired electrode location can thus lead to a faulty analysis of an individual's heart condition. Consequently a primary objective in electrocardiography is to precisely locate the electrode sensors in proximity to well defined anatomic landmarks. Once this has been accomplished, more meaningful data can be derived from the electrical potentials of electrocardiograph sensors.
It is thus desirable to provide an electrocardiograph sensor positioning device that provides data which assures repeatable locations of electrode sensors during subsequent electrocardiographic examinations and which establishes a location path for locating the electrodes in desired predetermined positions.